Questions and Answers
What is the name of the current that flows through a body when exposed to a touch voltage due to a fault?
Automatic disconnection of supply is required to:
The maximum disconnection time for a circuit supplying hand held class 1 equipment is:
The maximum disconnection time for a circuit supplying 25 amp 3 phase socket outlets is:
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The maximum disconnection time for a circuit supplying a hot water system is:
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The maximum disconnection time for a sub main circuit is:
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A device that is used to detect leakage current to earth (such as a person receiving an electric shock) and then disconnect the supply to prevent harm is called:
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Another name (acronym) for a device used to detect earth leakage current is:
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What is the sensitivity mA rating for RCD's to provide additional protection against electric shock as per AS3000?
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What is the sensitivity or mA rating for RCD's that may be used in higher risk installations such as bathrooms and kindergartens?
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What is a possible disadvantage of using a low setting (sensitivity) mA RCD?
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Which of the following is NOT regarded as a damp situation in AS3000 requiring additional safety precautions?
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The IP protection rating in AS3000 designates the degree of protection against:
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The lower the number in the IP rating, the higher the degree of protection.
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Which Zone relates to the area immediately above a bath, shower base or pool?
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The Zone with the lowest number has the highest degree of risk in a damp situation.
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What is the minimum distance above a sink?
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Study Notes
Protection against Indirect Contact
- Touch current is the current that flows through a body when exposed to touch voltage due to a fault.
- Automatic disconnection of supply ensures no touch voltages occur on exposed conductive parts to prevent electric shock.
- Maximum disconnection time for handheld Class 1 equipment is 0.4 seconds.
- For 25 amp 3-phase socket outlets, the maximum disconnection time is also 0.4 seconds.
- Hot water systems require a maximum disconnection time of 0.5 seconds.
- Sub main circuits should disconnect within 0.5 seconds.
- A Residual Current Device (RCD) detects leakage current to earth (like a shock) and disconnects the supply to enhance safety.
- ELCB (Earth Leakage Circuit Breaker) is another name for a device that detects earth leakage current.
- RCDs should have a sensitivity rating of 30mA for additional protection against electric shock as per AS3000 standards.
- Higher risk installations, such as bathrooms and kindergartens, should utilize RCDs with a sensitivity rating of 10mA.
- A disadvantage of using low sensitivity mA RCDs is that they may cause nuisance tripping due to small leakage currents in equipment.
- According to AS3000, a garden tap is NOT considered a damp situation requiring additional safety precautions.
- The IP protection rating indicates the degree of protection against solid objects and water.
- Lower numbers in the IP rating correspond to a lower degree of protection.
Electrical Zones
- Zone 0 refers to the area inside a bath, shower base, or pool; it has the highest risk of electric shock.
- Zone 1 is the area immediately above a bath, shower base, or pool.
- Zones are classified based on the level of risk in damp situations; lower numbered zones have the highest degree of risk.
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Description
Test your knowledge on the protection against indirect contact in electrical installations. This quiz will assess your understanding of safety measures and regulations required for safe electrical circuit management. Complete it to gauge your proficiency in this essential area of electrical engineering.
